Allergy information for: Tomato (Lycopersicon esculentum )

Tomato is eaten raw in salads or cooked as a vegetable and is a frequent ingredient in soups and stews. It is found in most pizzas. Tomato is used in sauces, pickles and chutney, which is often made from green tomato.

Allergy Information:More than 50 cases of food allergy after eating tomato have been reported. In general, tomato allergy is associated with allergy to either latex or pollen. The symptoms reported were rather different in the two groups. The patients with no latex allergy reported mostly the oral allergy syndrome with some skin reactions such as urticaria (hives). Patients with latex allergy reported urticaria as the most common reaction but 20% suffered anaphylaxis. Allergy to tomato is also linked to allergy to potato since they are related plants.

Reche et al. (2001) [927] studied a group (A) of 30 non-latex-allergic patients, and a group (B) of 10 latex-allergic patients. In group A, the most frequent clinical symptom with tomato was oral allergy syndrome (OAS), although urticaria was the most frequent symptom in group B. In this group, anaphylaxis occurred in 20% of the patients.

Positive reactions to tomato (39.2%) were observed in children with allergy to grass pollen. In children with positive skin test to tomato a 45% correlation with a positive RAST result were observed (de Martino et al. 1988) [950]

Tomato extract. To prepare this extract tomato pericarp was dissected and homogenized for 15 s in cold distilled water. After centrifugation at 2400 gfor 10 min, the pellet was collected and resuspended in 1 m NaCl at pH 6 with 1 m NaOH. After stirring for 3 h at 4 °C, the debris was removed by centrifugation at 2400 gfor 10 min. The supernatant was filtered and brought to 75% saturation with ammonium sulphate for 18 h. The precipitate was collected by centrifugation at 10 000 gfor 20 min and suspended in 0.15 m NaCl (pH 6). This extract was dialysed against 0.15 m NaCl (pH 6) at 4 °C over two nights. The residues were removed by centrifugation at 10 000 gfor 20 min. (Kondo et al. 2002 [949])

Tomato extract. To prepare the extract 200 g of ripe tomato was washed, ground, and soaked for 1 h in 500 ml of PBS with 10 mM ascorbic acid as an antioxidant. The mixture was stirred for 2 h at 4°C and centrifuged at 7000 g for 40 min at 4°C. The supernatant was dialyzed (molecular weight cutoff: >3500 Da) at 4°C for 24 h against glycine, centrifuged at 15 000 g for 30 min at 4°C, and filtered through a 0.45-µm filter. The material was lyophilized. (Reche et al. 2001) [927]

Forty patients with a history of adverse reactions to tomato. The patients were divided into two groups; group A comprising 30 non-latex-allergic patients, and group B comprising 10 patients with latex allergy (Reche et al. 2001) [927]

In RAST inhibition assays, the IgE binding from the sera from four out of five subjects with allergy to Japanese cedar pollen was inhibited by more than 50% by tomato fruit extracts. The IgE binding to tomato fruit was inhibited more than 50% by Japanese cedar pollen extracts in 3/5 sera. (Kondo et al. 2002) [949]

Tomato allergy was found to occur with a prevalence of about 9% in a group of birch pollen-allergic patients. Of the patients with adverse reactions to tomato, 44% presented IgE to tomato profilin and 35.5% specific IgE to CCD. Two patients were sensitized to a lipid transfer protein in tomato (Foetisch et al. 2001) [928]

Recombinant tomato profilin induced histamine release from human basophils in a range of 18-40% in a dose-dependent manner. Histamine release of up to 30% or 55% was obtained with the highest concentration of tomato extract. In the ELISA assays, 11 of 50 patients (22%) reacted with the purified recombinant tomato profilin (Westphal et al. 2004) [918]

Proteins were electrophoretically transferred to a PDVF membrane using a minitransfer chamber. Blots were incubated with pool sera diluted 1:1. Alkaline-phosphatase-conjugated goat anti-human IgE (1:2000) was added and incubated. The blot was developed with an alkaline-phosphatase-conjugate substrate kit of nitroblue tetrazolium and 5-bromo-4-chloro-3 indolyl-phosphatase (Recher et al. 2001) [927]

Out of 49 sera from German patients with tomato-related symptoms 18 (37%) recognized several bands above 20 kDa. From the Spanish group, 10 out of 29 (34.5%) sera showed reactivity in the high molecular mass range. The authors also detected binding to proteins with a molecular mass of 15 and 9 kDa (Westphal et al. 2003) [919]

Group A of patients reacted to a double protein band at 44 and 46 kDa, a triple band at 67 kDa, several proteins at 20 and 30 kDa; and a protein between 14 and 20 kDa. In pool B, the profile obtained was similar to pool A, except that it had two more bands at 14 and 17 kDa (Reche et al. 2001) [927]

The IgE binding to some protein bands from both Japanese cedar pollen and tomato fruit extracts are mutually inhibited, but the protein bands involved in this cross-reactivity differed between patients (Kondo et al. 2002) [949]

A protein with a molecular mass of 45kDa was strongly recognised by 67 % of the allergic patients (Weangsripanaval et al. 2003) [921]

Diaz-Peralez et al.(1999) identified a chitinase present in tomato. Patients with the latex fruit syndrome displayed IgE binding to a band that was also recognized by a chitinase specific antibody (IgE- immunoblots), suggesting that chitinases present in latex as well as in a range of fruits are one cross-reactive allergen responsible for the latex-fruit syndrome.

There are only few studies on the stability of profilins most of them on celery profilin. Compared to other allergens, profilin is a moderately stable protein, more resistant than Bet v 1 homologues but less stable than lipid transfer proteins or corss-reactive carbohydrate deteminants of glycoporein allergens.

Allergen properties & biological function:The allergen is tomato profilin which is thought to be an actin and phosphatidylinositol 4,5-bisphosphate binding protein involved in the regulation of the actin cytoskeleton and signal transduction.

Nature of main cross-reacting proteins:No cross-reactivity has been described

Allergen properties & biological function:Beta-Fructofuranosidase, also known as acid invertase (EC 3.2.1.26) catalyses the hydrolysis of sucrose into glucose and fructose. The Beta-fructofuranosidase of tomato was shown to play an important role in the regulation of hexose accumulation during fruit ripening

Allergen purification:

Lyc e 2 has been purified from lyophilized tomato extract by hydrophobic interaction chromatography and gel chromatography (Westphal et al. 2003) [919]. The same authors have cloned and expressed the cDNA of two different isoforms of the protein, Lyc e 2.01 and Lyc e 2.02 in E. coli. The recombinant proteins were purified by electroelution and refolded.